More civilians were killed last year in Afghanistan than at any time since records have been kept, according to a UN report released on Sunday.

There were 3,804 civilian deaths in the Asian country last year, 927 of whom were children, the UN's Assistance Mission in Afghanistan (UNAMA) said. That represents an 11% increase on the previous year.

The total number of civilian casualties reached nearly 11,000 as more than 7,000 people were also injured.

Tadamichi Yamamoto, the Secretary-General’s Special Representative for Afghanistan, said the "level of harm and suffering inflicted on civilians in Afghanistan is deeply disturbing and wholly unacceptable."

"All parties need to take immediate and additional concrete steps to stop a further escalation in the number of civilians harmed and lives destroyed," he added.

Spike in suicide attacks

UNAMA blamed the increase on a "spike in suicide attacks" by anti-government elements such as the Taliban insurgent group and the so-called Islamic State, who were responsible for 63% of casualties.

Kabul, the country's capital, was particularly impacted, with almost half of suicide and complex attacks from anti-government elements taking place there.

But about a quarter of casualties were the results of actions taken by the national security forces, the international military forces and pro-government armed groups.

"The fact that the number of children killed this year is the highest on record, is particularly shocking," Michelle Bachelet, the UN High Commissioner for Human Rights, said.

In addition to the lives lost, the dire security situation is preventing many Afghans from enjoying their economic, social and cultural rights, with thousands of children already handicapped for life because of attacks on schools and medical facilities," she added.

According to UNAMA, 32,000 Afghan civilians have been killed in the past decade and around 60,000 have been injured.